Bullet trap

ABSTRACT

In a bullet trap for indoor shooting with small arms, which bullet trap, behind the targets, includes a vertically suspended curtain (1) made of rubber, and a vertically supported impact plate (3) made of steel and being spaced behind the curtain, the space between the curtain and the impact plate is enclosed by cover plates (4, 4&#39;, 5, 6) extending forwards from the side, upper and lower margins of the impact plate, covering the space between the impact plate and the curtain, whereby the latter is sealingly attached to the front edges of the cover plates through steel profiles (9), attached to the cover plates by screwing through the curtain. The enclosed space is continuously evacuated by connected fan means (10) and an interconnected filter (12) to prevent that lead containing dust, which is set free upon the impact of the bullets in the bullet trap, is distributed to the air and the shooting premises.

The present invention relates to a bullet trap for indoor shooting,which trap significantly reduces the distribution of lead contaminateddust that is connected with indoor shooting.

Among shooters it is commonly known, that considerable amounts of leadcontaminated dust is set free upon shooting and accordingly mixed withthe air. The problem is of course particularly apparent in connectionwith indoor shooting, where the amount of lead in the breathing air canbe large enough to be detectable in the shooter's blood. This danger tothe health is so obvious and substantial that limitation of gun traininghave been discussed and also realized.

The lead particles that are set free upon shooting arise mainly from twosources: partly from the cap charge, which is believed to produce 30-40%of the distributed lead, partly from the bullet, which produces 60-70%of the lead.

At the firing moment, a certain amount of lead is detached from the backend plane of the bullet, where the bullet usually has no jacket and issubjected to high pressure and hot gases as it is pushed through thebore. This problem is sufficiently solved by attaching a separate plateto the end plane, which plate is folded over by the surrounding jacket,or by electrolythically applying a jacket material. The majordistribution of lead particles arise when the bullet hits the bullettrap, where the bullet is splintered and detached from its jacket.

Conventionally, the bullet trap comprises a vertically standing steelplate, with a thickness of 10-15 mm, in front of which a curtain made ofsynthetic fibres or rubber is suspended to prevent ricochets from thesteel plate. The bullet penetrates the curtain and is subsequentlysplintered against the plate. Through the contractibility of thematerial in the curtain, the bullet will only leave a very small hole inthe curtain. However, the curtain has no ability to shield the shootingrange from the lead contaminated air, which exists in the space betweenthe curtain and the steel plate. Due to the generation of heat, causedby the impact of the bullets with the plate, and due to the turbulencethat is caused by the velocity of the bullet, a considerable aircirculation is produced behind the curtain, whereby this air strives topass the curtain through openings at the floor, the ceiling and thesides of the curtain.

Among attempts to reduce the amount of lead in the air reference is madeto the procedure of suspending multiple curtains behind each other.Since each curtain contributes to the retardation of the bullet, it haslost sufficient energy not to splinter at the impact with the plate. Thedrawback of this solution is that it is very costly, because allcurtains must be simultaneously replaced when the target area hasreceived enough bullets to reduce the retardation effect.

Another solution to the problem is to install, behind the targets, abackwards tapering funnel of steel, with a circular drum connected toits back end taper. The bullets are trapped within the wide opening ofthe funnel, bounces backwards to the drum where they rotate till theyhave lost their energy, where upon they fall out of the drum, and arecollected, comparatively undamaged. On the inside, the funnel issprinkled with water or oil spray to produce a lubricating effect thatwill spare the funnel and the drum and to flush the bullets out of thebullet trap. The draw back of this solution is likewise the great costsand the funnel also requires a large installation space which precludesthe utilization of the funnel in most existing shooting premises.

To reduce the amount of lead particles in the air, the present inventionprovides a device which readily can be installed in existing shootingpremises through being space saving, and which is not associated withabove said great costs for replacement of curtains for the bullet trap.

Briefly, the invention includes forming of a closed space between thecurtain and the steel plate, and connecting the closed space to a devicefor continuous evacuation and dust separation.

Accordingly, the object of the invention is to provide a closed spacefor trapping the bullet, which space is shielded from the shooter,continuously evacuated and cleaned from lead particles.

This object is met with in a device according to claim 1.

The invention will now be described more in detail in conjunction withthe attached drawing, illustrating a preferred embodiment of theinvention, showing in

FIG. 1 a diagrammatic, partly fragmentary perspective view of apreferred embodiment of the bullet trap of the invention.

In the preferred embodiment, the inventive bullet trap comprises avertically suspended curtain 1, positioned behind the target andattached to a steel frame, commonly referred to by the reference number2. The curtain 1 is made from synthetic material or non-reinforcedrubber and is composed from several lengths, vulcanized together to forman integrated curtain 1 of required width. The frame 2 is mounted to avertically standing impact plate 3, which is positioned behind andspaced from the curtain 1, and on to which the bullets are splintered onimpact. The word "vertically" should here be understood as substantiallyvertically oriented to the floor, and may also include an impact plate 3which comprises a slanting or inclined orientation, thus directing thericochetting bullets downwards or upwards. The frame 2 is for exampleattached to the impact plate 3 by welding, and extends forward from theside, lower and upper edges of the plate, and the distance between thecurtain 1 and impact plate 3 is optional but is preferably chosen to beabout 60 cm. The frame 2 includes flat, covering side plates 4, 4', aflat roof plate 5 and a bottom plate 6, wherein the later is formed withtapering hoppers 7. Detachable boxes 8 for collecting the bullet andjacket remains are coupled to the lower end of a resp. hopper 7. Theboxes 8 can for example be slidably supported in guide rails in thelower edges of the hoppers, or be suspended with the aid of hooks orclamps, whereby it must be made sure that the connections are air tight.The fastening of the boxes is however an easy task for a man skilled inthe art of mechanics, and is not shown in detail since it is not crucialfor explaining the operation of the bullet trap. The curtain 1 isperipherally sealed to the cover plates 4, 4', 5 and to the bottom plate6 for example with the aid of externally positioned steel profiles 9, asis shown in the drawing, wherein the profiles 9 are secured by boltswhich are screwed through the curtain 1 and into inwardly bent sectionsof the front edges of the cover plates and of the bottom plate.Alternatively, the curtain is attached to the frame by folding itsmargin sections onto the outside of the cover plates and bottom plate(not shown in the drawing). In one preferred embodiment, the inwardlybent sections of the front edges of the cover plates comprise fixed,protruding and threaded bolts, on to which the curtain is suspendedthrough corresponding holes, where upon the steel profiles 9 are securedby nuts. By this arrangement is formed a closed space for trapping thebullets, a space which is shielded from the shooter.

The bullet trap is connected, for example through one of the side plates4, to an evacuation equipment or a fan assembly 10, for evacuating theclosed space between the curtain 1, the steel plate 3 and the coverplates 4, 4', 5 and 6 through a duct 11. On its way to the fan assembly10, the lead contaminated air from the closed space passes uninterconnected dust separation unit or a filter 12, in which particlesare trapped and removed from the air. The evacuation equipment 10 andthe dust separation unit 12 are of conventional and commerciallyavailable construction, and can for example be of the type that is soldunder the trademark Dustcontrol. The cleaned air is then optionallyreturned to the shooting premises or passed to the open air outside. Thebullet trap includes an air inlet 13, for example as in FIG. 1 attachedto the roof plate 5, through which the evacuated air is replaced. It isnaturally within the scope of invention to design an embodiment,comprising more than one fan assemblies and dust separation units ormore than one evacuation ducts or air inlets, in cases where this isconsidered to be required for example due to the dimensions of thebullet trap.

The complete bullet trap can be suspended in chains or rods (not shown),connected to loops 14, which are protruding from the frame 2. The bullettrap can also as is shown in the drawing be supported by two or moresupport members 15, attached to the side plates 4, 4' and to the sideedges of the impact plate 3, e.g. by welding. The support members canalternatively be equipped with wheels to make the assembly easy to move.

The bullet trap has generally a height of about 1.5-2 m, and the widthvaries to the number of targets or gun ranges. In order to stabilize therubber mat or curtain 1 and support it so as not to curve inwards as aresult of a possibly lower pressure in the closed space behind thecurtain, the later can advantageously be equipped with vulcanized,vertically attached support strips 16 made of rubber, between eachtarget area.

In shooting premises with existing bullet traps in the form of fixedlymounted impact plates, the invention can be practiced by mounting thecover plates 4, 4', 5 and bottom 6 to the existing impact plate.

When advantageous, the invention can even be practiced in an embodimentwhich includes that the closed space between the curtain 1 and theimpact plate 3 is formed by a front wall, detaching a space from theshooting premises. Curtain 1 is sealingly attached to the wall frame, inthe side, upper and lower margins of the wall. Slidably mounted boxesnear the floor facilitates removal of bullet and jacket remains. In thisembodiment, the evacuation equipment and the dust separation unit areplaced on the outside of the shooting premises, and the evacuation ductpasses the wall of the housed shooting range. This embodiment isparticularly well adapted for creating the closed, evacuated spacebetween the curtain 1 and the impact plate 3 in the case where thebullet trap is equipped with an angularly mounted plate, against whichthe bullet ricochets downwards, and therefore requires a longerinstallation depth for the assembly.

With the inventive bullet trap a significant reduction of the amount oflead particles in the air is achieved. With the high capacity ofexisting dust separation equipments and by using lead free caps andbullets with completely surrounding jackets, lead contamination of theair in the shooting premises can practically be eliminated incombination with the invention, even if the cleaned air is returned tothe housed shooting range. A positive side effect is also that the noisefrom the bullets impact in the bullet trap is reduced, which of courseis advantageous for the surroundings.

I claim:
 1. A bullet trap for indoor shooting including, a vertically suspened curtain (1) and a substantially verticaly supported impact plate (3), spaced behind the curtain, characterized bythe space between curtain (1) and the impact plate (3) being enclosed and shielded from the shooting premises in which the trap is located, and by fan means (10) connecte to the enclosed space for continuously evacuating air therefrom and a dust separation unit (12) for cleaning lead particles from the evacuated air.
 2. Bullet trap according to claim 1, characterized bya frame (2) with side top and bottom cover plates (4, 4', 5, 6) attached to the impact plate (3), wherein the cover plates extend forward from the side, upper and lower margins of the impact plate, the curtain (1) being sealingly attached to the front edges of the cover plates (4, 4',5, 6) through outwardly positional steel profiles (9), secured by bolts to the plates (4, 4', 5, 6), through the curtain (1), the fan means (10) and dust separation unit (12) being interconnected and being connected to the enclosed space through one or some of the cover plates (4, 4', 5) by at least one evacuation duct (11), and at least one air inlet (13), connected to the enclosed space through at least one of the cover plates (4, 4', 5).
 3. Bullet trap according to claim 2, characterized byat least one hopper (7) formed in the bottom plate at least one box (8) for collecting bullet and jacket remains detachably supported in the lower end of the hopper (7), formed in the bottom plate (6), and by the bullet trap comprising suspension means in the form of loops (14) and/or support members (15).
 4. Bullet trap according to claim 1 characterized byat least a bottom plate (6) extending forwardly from the lower margin of the impact plate, at least one hopper (7) formed in the bottom plate at least one box (8) for collecting bullet and jacket remains detachably supported in the lower end of the hopper (7), and the bullet trap comprising support means in the form of suspension loops (14) and/or support members (15). 